typedef int STDataType;// typedef定义STDataType类型

typedef struct Stack
{
	int* a;       // 定义动态存储数组
	int top;      // 记录栈顶    
	int capacity; // 记录容量
}ST;

2.2 栈的初始化

void StackInit(ST* ps)
{
	assert(ps);

	ps->a = NULL;
	ps->top = 0;
	ps->capacity = 0;
}

2.3 入栈

void StackPush(ST* ps, STDataType data)
{
	assert(ps);

	// 判断是否栈满，栈满则需要扩容
	if (ps->top == ps->capacity)
	{
		int newCapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
		ps->a = (STDataType*)realloc(ps->a, newCapacity * sizeof(STDataType));
		if (ps->a == NULL)
		{
			printf("realloc fail\n");
			exit(-1);
		}
		ps->capacity = newCapacity;
	}

	ps->a[ps->top++] = data;
}

2.3 出栈（压栈）

void StackPop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);
	
	ps->top--;
}

2.4 获取栈顶元素

STDataType StackTop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);

	return ps->a[ps->top - 1];
}

2.5 获取栈中有效元素个数

int StackSize(ST* ps)
{
	assert(ps);

	return ps->top;
}

2.6 检测栈是否为空

bool StackEmpty(ST* ps)
{
	assert(ps);

	return ps->top == 0;
}

2.7 栈的销毁

void StackDestroy(ST* ps)
{
	assert(ps);

	free(ps->a);
	ps->a = NULL;
	ps->capacity = ps->top = 0;
}

3. 栈的使用

void test()
{
	ST st;
	StackInit(&st);

    // 入栈
	StackPush(&st, 1);
	StackPush(&st, 2);
	StackPush(&st, 3);
	StackPush(&st, 4);
	StackPush(&st, 5);

    // 输出栈中的值，每输出一个，就出栈一个
	while (!StackEmpty(&st)) // 当栈为空时停止输出
 	{
		printf("%d ", StackTop(&st));
		StackPop(&st);
	}

	StackDestroy(&st);
}

4. 完整源码

Stack.h

#pragma once

#include <stdio.h>
#include <assert.h>
#include <stdbool.h>
#include <stdlib.h>

typedef int STDataType;

typedef struct Stack
{
	int* a;
	int top;
	int capacity;
}ST;

// 初始化栈
void StackInit(ST* ps);
// 入栈
void StackPush(ST* ps, STDataType data);
// 出栈
void StackPop(ST* ps);
// 获取栈顶元素
STDataType StackTop(ST* ps);
// 获取栈中有效元素个数
int StackSize(ST* ps);
// 检测栈是否为空，如果为空返回非零结果，如果不为空返回0 
bool StackEmpty(ST* ps);
// 销毁栈
void StackDestroy(ST* ps);

Stack.c

#include "Stack.h"

void StackInit(ST* ps)
{
	assert(ps);

	ps->a = NULL;
	ps->top = 0;
	ps->capacity = 0;
}

void StackPush(ST* ps, STDataType data)
{
	assert(ps);

	if (ps->top == ps->capacity)
	{
		int newCapacity = ps->capacity == 0 ? 4 : ps->capacity * 2;
		ps->a = (STDataType*)realloc(ps->a, newCapacity * sizeof(STDataType));
		if (ps->a == NULL)
		{
			printf("realloc fail\n");
			exit(-1);
		}
		ps->capacity = newCapacity;
	}

	ps->a[ps->top++] = data;
}

void StackPop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);
	
	ps->top--;
}

STDataType StackTop(ST* ps)
{
	assert(ps);
	assert(ps->top > 0);

	return ps->a[ps->top - 1];
}

int StackSize(ST* ps)
{
	assert(ps);

	return ps->top;
}

bool StackEmpty(ST* ps)
{
	assert(ps);

	return ps->top == 0;
}

void StackDestroy(ST* ps)
{
	assert(ps);

	free(ps->a);
	ps->a = NULL;
	ps->capacity = ps->top = 0;
}

test.c

#include "Stack.h"

void test()
{
	ST st;
	StackInit(&st);
	StackPush(&st, 1);
	StackPush(&st, 2);
	StackPush(&st, 3);

	printf("%d ", StackTop(&st));
	StackPop(&st);

	StackPush(&st, 4);
	StackPush(&st, 5);

	while (!StackEmpty(&st))
	{
		printf("%d ", StackTop(&st));
		StackPop(&st);
	}

	StackDestroy(&st);
}

int main()
{
	test();

	return 0;
}